Other than having to drop every single object on the floor and then do it by looking at them from the base building menu. Like you can with weapons and armour at crafting tables.....?

I don't think so. But if it's on you when you go to mod a weapon or whateverthose junk items show as scrap materials so really no need to put it on the floor and junk every item

Can't you get materials in the town building mode that literally lets you scrap everything in the environment from trees, to cars, ruined houses, etc.

that also took me some time to figure out...just throw everything into the workbench - doesnt matter if they are scrapped or not - they are usable immediatly

Yes, then you make something you will get an overview over sources used and this includes junk.
Weapon and armor has to be broken down to be recycled as far as I know.

Ahhhh, ok, cool, that's fine. How do we put things into a workbench though? Also which workbench, just any?